The Tow Package is actually more than a receiver and plug. For my generation of F-150 (I haven't looked at the current Gen to see what's different), it added an auxiliary transmission cooler and bigger radiator, as well as the SelectShift option (which adds the upshift/downshift rocker switch to the shifter and the gear readout on the dash) and Trailer Sway Control. It sounds like you're probably not going to exceed 5K lbs of trailering, which means pretty much any F-150 will have you covered. (Heck, the Explorer would cover that much.) The capabilities of a modern F-150 would be closer to an F-250 of your truck's vintage--my dad's new F-150, f'rinstance, has a payload rating of over 2,000lbs. You can't go wrong with either EcoBoost V6 or the Coyote 5.0 V8.